Filed Under Water

Watering the Desert

Arizonans often joke that whiskey is for drinking, water is for fighting. Water's value to the state was made evident by the 1934 "war" with California as well as by longstanding disputes with neighboring states over the allocation of the Colorado River. The network of Phoenix-area canals was built over time to take advantage of every drop of water diverted to the desert. This network is larger than the network of canals in either Amsterdam or Venice!

The Salt River Valley canal system began with the extensive irrigation projects dug by the Hohokam. Their canals were rebuilt and extended in the nineteenth century by the Salt River Project (SRP). The Roosevelt Dam provided Arizona's first source of hydropower, used originally for its own construction and then for the wider Valley, setting in motion the "reclamation principle" of power as the paying partner of water. The hydropower at Arizona Falls also provided some of the Valley's first electricity.

The water carried in the canals originates as snowpack in the mountains more than 60 miles east of Phoenix. The canals south of the Salt River were the first to be irrigated into verdant oases. Built from 1883 to 1885, the Arizona Canal has provided the lands north of the Salt River with water for cultivation, and the old and new crosscut Canals tied the north and south canal systems together by 1913.

The 1968 passage of the Colorado River Basin Project Act authorized the construction of a 336-mile long Central Arizona Project canal system. The CAP canal diverts water from the state's western border to the Phoenix and Tucson areas and was completed in Phoenix in 1985 and in Tucson in 1993.

edited 12/23/2019:wt


Dedication of Roosevelt Dam The Theodore Roosevelt Dam was the first major structure constructed by the Bureau of Reclamation on the Salt River Project. Source: Library of Congress Date: 1911


The Power of Water Jim Duncan tells the story behind the Arizona Falls, including the excavation of the falls in the 19th century and how the falls functioned as a hydroelectric facility from 1902 through 1950. Written by Amy T. Long; narrated by Jim Duncan. Recorded at Scottsdale Channel 11; courtesy of the Papago Salado Association.


Arizona Falls
Arizona Falls Prior to the construction of an on-site power plant, Arizona Falls sits at a natural 20-foot drop in the canal system. Source: SCOT-HIST-2009-0285; Scottsdale Public Library Date: 1902
Arizona Canal Excavation
Arizona Canal Excavation Workers excavating the Arizona Canal eight miles northeast of Phoenix, with Camelback Mountain in the background. Source: HAER No. AZ-19-4; Historic Engineering Record, Library of Congress
Theodore Roosevelt in Arizona
Theodore Roosevelt in Arizona President and Rough Rider leader Theodore Roosevelt authorized the Newlands Reclamation Act in 1901 for constructing large-scale water control systems in the western US. He traveled to Arizona to speak at the March 18th, 1911 dedication of Roosevelt Dam, the first dam to control the Salt River. Now in a system with four other dams, it helps prevent droughts and flooding. Source: Library of Congress Date: 1911
Granite Reef Dam
Granite Reef Dam The Granite Reef Dam was completed in 1908 for the Salt River Project. It replaced an older dam that washed out in a flood. The dam diverts most of the Salt River into the Arizona Canal and Eastern Canal for irrigation and drinking water in metro Phoenix. Source: HAER No. AZ-19-13; Historic American Engineering Record, Library of Congress. Date: 1930



John Larsen Southard, Mark Tebeau, and Amy Long, “Watering the Desert,” Salt River Stories, accessed May 19, 2024,